How can i create a color vector for markers in a scatter plot?

I have two vectors X,Y. I would like to make a scatter plot scatter(x,y,s,c), but i don't have a C vector. So my quaestion is, how can i make a C-vector with the same lenght as my other vecotrs in such a way that i get the right color settings on my plot.

Answer 1

[Arnaud Miege]

It depends what you mean by the "right colour settings". The following will give you a C matrix of the right size, but whether that's the colour settings you expect, it's another question:

C = rand(length(x),3);
scatter(x,y,s,C); % where x, y and s are already defined

Arnaud

[Bernt Milne]

Thank you for your reply. What i ment was that i want the color of the dots to represent the number of points with a given size(Y) and postition(X). Do you know how to do that?

[Arnaud Miege]

I think you can do one or the other but not both at the same time. The following will colour the scatter plot based on the number of point with a certain y:

load seamount

n = hist(y,length(x));

scatter(x,y,5,n)